Set setuptools scm fallback version.

Sometimes such as downloading code directly without git repo, python packaging
will fail as setup tools failed to determined the version, to avoid such
failure, we need to add an fallback version for it.

PR: USTC-KnowledgeComputingLab/qmb#32
Signed-off-by: Hao Zhang <[email protected]>

Author: hzhangxyz

pyproject.toml

@@ -64,6 +64,7 @@ qmb = ["*.cpp", "*.cu"]
 [tool.setuptools_scm]
 version_file = "qmb/_version.py"
 version_scheme = "no-guess-dev"
+fallback_version = "0.0.0"
 
 [tool.yapf]
 based_on_style = "google"